It's up to the individual shooter.1/2x1/2 has less clicks to count, but is less precise. 1/4x1/4 is the corollary...more accurate in adjustment, but twice as many clicks to count and keep track of when you go to the next target distance..030 or .040 on the aperture is a matter of your eye sight, normal range conditions, etc...the bigger the hole, the greater the light transfer but the less tight/precise the sight picture.Thanks.Steve/RRA